The present invention relates to a sealing device for sealing two concrete pipe end portion in relation to each other.
For providing a tight connection between concrete pipes there are often used socket pipes forming at one end a socket and at the other end a spigot, two pipes being jointed by introducing the spigot of one of the pipes into the socket of the other pipe. Thereby, a sealing surface in the socket of one of the pipe end portions and a sealing surface on the spigot end of the other pipe end portion introduced into the socket together form a sealing space which is connected with the interior of the pipe end portions. In the sealing space there is positioned an elastic material sealing element which is compressed between two opposite sealing surface portions of the sealing space.
Concrete pipes of this kind are used for example for conveying waste water. It happens that the waste water contains aggressive substances, for example marsh gas or sulphurous gas effecting and degrading the concrete material of the pipes. It is possible to extend the life of the pipes by increasing the thickness of the pipe walls but a degradation of the concrete material in the areas of the sealing devices between the pipes inevitably leads to defective tightness of the pipe joints. This depends on the fact that the degradation of the sealing surfaces provides an increased width of the sealing space so that the compression of the sealing element necessary for the function thereof is successively decreased and lost.
The object of the invention is to provide a sealing device for concrete pipes making it possible to convey by means of the pipes mediums containing substances which are detrimental to the concrete without causing the risk of jeopardizing the function of the sealing device.